Authors: Fahri SÖNMEZ, Hatice EGE, Hayrettin OKUT
Abstract: This research was conducted in 1987-1988 at Department of Agronomy, Faculty of Agriculture, University of Ege. The aim of this research was to study the effects of Terpal plant growth regulator on yield and yield components of four barley cultivars. For this purpose, 0 and 2 lt/ha dosages of Terpal plant growth regulator was applied on barley cultivars Kocaoglu, Tokak-157/37, Quantum and Cumhuriyet-50 in tillering (Feeks scale-4) and shooting (Feeks scale-7) stages. The path and stepwise regression analysis techniques were applied to data, to determine the causal relations and traits that are more effective to explain on changes of variation grain yield. In conclusion from both path and stepwise regression analysis that the number of spike per m2 among all yield components is most effective factor on the variation in grain yield of barley cultivars.